1. Field of the Invention
The present invention relates to a structure for mounting a three-point type seatbelt for a vehicle.
2. Description of the Related Art
One sort of conventional three-point type seatbelt system is so designed that one end portion 1a of a seatbelt 1 is fixed and cannot be disengaged from a side portion 5 in the upper part of the vehicle body of a pillar-less type four- or two-door car, as shown in FIG. 5, even when the front passenger's seat is unoccupied. This type of seatbelt system therfore obstructs the driver's side view, as well as that of any occupant seated in the back seat, while also marring the appearance of the car and making the occupants feel uncomfortable.
In order to overcome the above disadvantage, a disengageable three-point type seatbelt system has already been proposed, such as that shown in FIGS. 6a to 6d.
This seatbelt system employs the "Apparatus for Housing Engaging Support Member of Three-Point Type Seatbelt" disposed in the specification of Japanese Utility Model Application No. 49851/1984 which has been filed for patent by the applicant of the present invention. In this seatbelt system, an engaging support member 4' of a three-point type seatbelt 1 has one end 4a thereof pivotally connected to a roof side rail 5 through a ceiling member 24 and has a tongue receiving port 25 formed at the other end 4b. The support member 4' is mounted such that when the seatbelt 1 is out of use, the support member 4' is pivoted about the end 4a so that the axis of the member 4' is substantially parallel with the plane of the roof 26. The seatbelt 1 is housed in a body side member 27 and has a tongue plate 2' for insertion into the tongue receiving port 25 formed at the end 4b of the support member 4', the tongue plate 2' being slidably engaged with the intermediate portion of the seatbelt 1a. One end 1b of the seatbelt 1 is wound into a retractor 28, while the other end is secured to a floor member of the vehicle. A recess is formed in a side portion 29 of the ceiling member 24 which is closer to the roof side rail 5 so that the recess extends substantially parallel with a side surface 50 of the rail 5. A closure portion 30 for closing the tongue receiving port 25 of the support member 4' is formed at the rear end of the recess.
There has also been proposed one type of structure for mounting a three-point type seatbelt for a vehicle wherein when the seatbelt is out of use, the engaging support member 4' is accommodated in or drawn close to the roof side rail 5 in the upper part of the vehicle body, while the seatbelt 1 is accommmodated in or drawn close to the nearest door or the vehicle body, thereby enlarging the usable space within the vehicle when the seatbelt 1 is out of use, and improving the visibility through the window as well as the external appearance. This type of mounting structure is arranged as shown in FIGS. 7a and 7b.
The illustrated arrangement is the "Three-Point Type Seatbelt for Vehicle" disclosed in the specification of Japanese Utility Model Publication No. 49788/1981, in which an anchor plate 4" is pivotally connected to a roof side rail 5 and a mounting bracket 9' secured thereto by means of a bolt 6' and a weld nut 13. The anchor plate 4" is biased so as to pivot in the direction of the arrow D shown in FIG. 7a by means of a coil spring 31. Further, a tongue 2" which serves as a fitting member is formed directly at the distal end portion of the anchor plate 4", and the tongue 2" is disengageably fitted to a buckle 3' provided on the seatbelt 1.
The bracket 9' is provided with embossed convex portions 32, 33 at two positions, respectively, while the anchor plate 4" is provided with a concave portion 34 which selectively engages with the convex portions 32, 33. The convex and concave portions 32, 33 and 34 in combination serve as means for positioning the anchor plate 4" at two extremities of its pivoting motion so that the anchor plate 4" is allowed to pivot through about 110.degree., as shown by the solid line and the broken line in FIG. 7a.
When the seatbelt 1 is to be used, the concave portion 34 of the anchor plate 4" placed in the broken-line position is disengaged from the convex portion 33 against the force of the coil spring 31, and the anchor plate 4" is pivoted in the direction of the arrow E so that it reaches the solid-line position and the concave portion 34 engages with the convex portion 32 so as to be retained thereby. When, in this state, the anchor plate 4" is slightly moved in the direction of the arrow E so that the concave portion 34 is disengaged from the convex portion 32, the anchor plate 4" is pivoted through about 110.degree. in the direction of the arrow D by the action of the coil spring 31, so that the concave portion 34 engages with the convex portion 33, and the anchor plate 4' is thereby fixed. In this way, the anchor plate 4" pivots upwardly from the window portion of the vehicle as shown by the arrow D and reaches the housed position shown by the broken line.
Thus, when the seatbelt 1 is out of use, it is completely withdrawn from the range of view defined by the window. It is therefore possible to provide a satisfactory side view for the occupant of the back seat, ensuring his comfort and ease of mind. Additionally, in the case of a two-door car, no obstruction is caused for the occupant when entering and leaving the vehicle.
However, with the structure of the prior art shown in FIGS. 6a to 6d, it is not possible for the occupant to feel the registration of the engaging support member 4' at the relevant positions where it is accommodated when pivoted to the two desired locations shown by the broken line and the solid line in the drawing.
In the prior art shown in FIGS. 7a and 7b, although the embossed convex portions 32, 33 are provided on the mounting bracket 9', and the concave portion 34 provided on the anchor plate 4" is selectively engaged with the convex portions 32, 33, it is still impossible for the occupant to feel any recognizable registration when he pivots the anchor plate 4" to the solid-line and broken-line positions, which fact inevitably involves inferior operability. In addition, when the anchor plate 4", which constitutes a cant rail, is pivoted about the bolt 6' in the direction of the arrow E shown in FIG. 7a to the solid-line position, it is not possible to reliably stop the anchor plate 4" from pivoting beyond the solid-line position in the direction of the arrow E toward the front end of the vehicle solely by means of the selective engagement between the concave portion 34 provided on the anchor plate 4" and the convex portions 32, 33 provided on the bracket 9'. Accordingly, an appropriate stop mechanism is required to enable the seatbelt 1 to be effectively used and fitted the body of the occupant in an optimum condition.